The present invention relates to testing and evaluation of subterranean formation fluids and, more particularly, to apparatus and method for improved fluid sampling.
It is well known in the subterranean well drilling and completion art to perform tests on formations penetrated by a wellbore. Such tests are typically performed in order to determine geological or other physical properties of the formation and fluids contained therein. For example, parameters such as permeability, porosity, fluid resistivity, temperature, pressure and saturation pressure may be determined. These and other characteristics of the formation and fluid contained therein may be determined by performing tests on the formation before the well is completed.
To evaluate prospects of an underground hydrocarbon reserve, a representative sample of the reservoir fluid may be captured for detailed analysis. In a typical sampling procedure, a sample of the formation fluids may be obtained by lowering a sampling tool having a sampling chamber into the wellbore on a conveyance such as a wireline, slick line, coiled tubing, jointed tubing or the like. When the sampling tool reaches the desired depth, one or more ports are opened to allow collection of the formation fluids. The ports may be actuated in a variety of ways such as by electrical, hydraulic or mechanical methods. Once the ports are opened, formation fluids travel through the ports and a sample of the formation fluids is collected within the sampling chamber of the sampling tool. After the sample has been collected, the sampling tool may be withdrawn from the wellbore so that the formation fluid sample may be analyzed.
It is important to obtain a sample of the formation fluid that is representative of the fluids as they exist in the formation with minimal contamination and without flashing the sample. Conditions that cause the fluid sample to approach or drop below saturation pressure create the possibility of asphaltene deposition and flashing of entrained gasses present in the fluid sample. There is need for some mechanism which will allow a zero flash sample to be taken but avoid the contamination of the sample.
While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.